# str="aabaa"
# str=list(str)
# n=0
# for i in range(0,len(str)//2):
#     for j in range(len(str)-1,len(str)//2, -1):
#         print(i,j)
#         if str[i]==str[j]:
#             n=j
#             break
#         else:
#             print("不是回文")
#     if i==n:
#         print(f"{str}是回文")

# str1 = "abc"
# print(str1[::-1])

# print(7//2)

# for j in range(5,3):
#     print(j)

str = "aabaa"
i = 0
count = 1   #标志位
while i <= (len(str)/2):
    if str[i] == str[len(str)-i-1]:
       # count = 1
        i += 1
    else:
        count = 0
        break
if count == 1:
    print('您所输入的字符串是回文')
else:
    print('您所输入的字符串不是回文')